This specification relates to Internet search systems.
Internet search engines aim to identify Internet resources, e.g., web pages, images, text documents, or multimedia content, that are relevant to a user's needs and to present information about the resources in a manner that is most useful to the user. Internet search engines return a set of search results in response to a user submitted query. Internet search engines generally include one or more services that can classify particular received queries. Such services may include services that classify queries as one or more of: a query that is pornographic, i.e., is seeking pornographic results or for which a large number of search results identifying resources that have been classified as pornographic are returned; a query that is navigational to a particular resource, i.e., is seeking that particular resource; a query that is a local query, i.e., is seeking information about a business located near the user; or a query that is seeking a particular item of information, e.g., is looking for an item of information that is an answer to a question posed in the query.